Polymers and methods for their preparation

Abstract

The present invention relates to a novel polyvinylamine polymer, its method of preparation and use, in particular in the papermaking field.

Description

Technical Field

[0001] This invention relates to a novel polyethyleneamine polymer, its preparation method, and its uses, particularly in the field of papermaking. Background Technology

[0002] The paper industry has been seeking to improve its methods of manufacturing paper, paperboard, or similar products, specifically in terms of cost reduction, yield, productivity, and even the properties of the final product.

[0003] Water-soluble polyamines produced by the degradation of Hofman polymers are known and widely used in papermaking processes, specifically to improve drainage during paper formation and enhance their dryness resistance. These polymers offer improved performance in various applications, but they also enable increased paper machine speeds, thereby increasing productivity.

[0004] Hofman degradation, discovered by Hofman in the late 19th century, is a reaction that allows functional groups (e.g., amides) to be converted into primary amine functional groups with one less carbon atom. The reaction mechanism is detailed below.

[0005] In the presence of a base (such as baking soda), a proton is removed from the amide.

[0006]

[0007] The resulting amidate then reacts with the active chlorine (Cl2) of hypochlorite (e.g., NaClO in equilibrium). The process generates N-chloramide. A base (NaOH) removes a proton from the chloramide to form an anion. The anion loses the chloride ion to form nitrene, which is then converted to isocyanate.

[0008]

[0009] Carbamates are formed through the reaction between hydroxide ions and isocyanate ions.

[0010]

[0011] After decarboxylation (removal of CO2) of urethane esters, primary amines are obtained.

[0012]

[0013] For the conversion of all or part of the amide functional groups in polymers containing amide groups as amine functional groups, two main coefficients (expressed in molar ratios) are involved. These coefficients are:

[0014] - Coefficient α = hypohalite (alkali metal hypohalite and / or alkaline earth metal hypohalite)

[0015] / amide functional group (and, if applicable, nitrile);

[0016] - Coefficient β = hydroxide (alkali metal hydroxide and / or alkaline earth metal hydroxide) / hypohalate (alkali metal hypohalate and / or alkaline earth metal hypohalate).

[0017] Although Hofman degradation initially involved amide groups, it can also be applied to nitrile functional groups (-C≡N), specifically the nitrile functional groups of acrylonitrile polymers.

[0018] Generally, the effectiveness of Hofman-degradable polymers as dry strength agents increases with their cationicity. That is, to increase their cationicity, the polymer used must possess high degradability. In fact, depending on the degree of α-degradation, different levels of cationicity can be produced, related to the number of amine functional groups formed on the polymer's carbon backbone.

[0019] The cationic nature of the degraded polymer may be caused by the protonable amine groups formed, but it may also be caused by the presence of cationic monomers.

[0020] Until recently, a heavy method (EP 377313) was developed that uses only the Hofmann degradation product production unit in situ, or a method that uses another polymer (N-vinylformamide polymer base, followed by hydrolysis) (US2004 / 118540) (which is also very expensive).

[0021] The first viable industrial solution was proposed in early 2005 in the applicant's document WO2006075115. In this document, the Hofman degradation products described are organic polymers generated at concentrations greater than 3.5% by weight. Although the polymers described herein can significantly improve dry strength properties, they have very low molecular weights, making their impact on applications such as drainage or flocculation very limited.

[0022] The applicant's documents WO2008 / 107620 and WO / 2010 / 061082 partially address the problem of poor drainage performance. However, the polymers described in these documents exhibit some leveling-off properties in terms of drainage and retention.

[0023] The applicant's document WO 2009 / 013423 also proposes a post-treatment of the polymers produced by the Hofman reaction to improve drainage performance. This post-treatment involves post-branching the copolymers obtained through Hofman degradation in the presence of at least one multifunctional branching agent. However, this method has significant limitations, including highly complex post-branching control (difficult to industrialize) and saturation performance at dosages greater than 1.5 kg of active material per ton of paper.

[0024] The applicant’s document WO 2011 / 015783 proposes a novel polymer that allows for the reduction (push back) of saturation properties, particularly for high strength, at approximately 2 kg of active material per ton.

[0025] Document US10,730,989 relates to a method for preparing an additive for papermaking based on (meth)acrylamide copolymers.

[0026] Despite all these improvements, persistent problems related to Hofman degradation remain. The dual treatment—first alkaline, then acidic—combined with temperature, leads to a significant decrease in the viscosity of the base polymer. Polymers obtained in this manner exhibit reduced application properties.

[0027] The applicant has surprisingly discovered that the method of the present invention allows for the synthesis of polymers in a way that increases the molecular weight of the base polymer without affecting its viscosity. Compared to existing solutions in the prior art, this increase in the molecular weight of the base polymer appears to provide paper with improved application properties in terms of dry strength, while also improving drainage, thus enabling increased paper machine speed and thereby increasing productivity.

[0028] The use of the polymers obtained by this invention is part of the general principles of product performance improvement, and more specifically, part of dry strength and drainage properties. The improved properties of the polymers according to the invention make it possible to reduce the amount of product required for applications, thus involving a reduction in greenhouse gas emissions, such as CO2, associated with the manufacture and use of synthetic polymers. Furthermore, the improved drainage properties reduce the amount of energy required. Summary of the Invention

[0029] This invention relates to a polyethyleneamine polymer obtained by Hofman degradation of a base polymer, the polyethyleneamine polymer comprising:

[0030] -At least one cationic monomer A;

[0031] - At least one nonionic monomer B, selected from acrylamide, acrylonitrile, methacrylamide and mixtures thereof;

[0032] - At least one structured system comprising:

[0033] At least one compound selected from the following: allyl sulfonic acid, methyl allyl sulfonic acid, allyl disulfonic acid, methyl allyl disulfonic acid, their salts, and mixtures thereof;

[0034] At least one compound II of formula (1):

[0035]

[0036] R1 and R2 are independently hydrogen atoms, methyl, ethyl, isopropyl or CH2-OH groups;

[0037] R1 and R2 are not both hydrogen atoms (when R2 = H, R1 ≠ H; when R1 = H, R2 ≠ H).

[0038] -Optionally, at least one monomer C: a nonionic monomer that is different from monomer B and different from compound II; a zwitterionic monomer or a hydrophobic monomer;

[0039] -Optionally, at least one crosslinking agent;

[0040] -Optionally, at least one transfer agent.

[0041] The polyethyleneamine polymer is obtained according to the following steps:

[0042] a) forming a solution (S1) comprising at least a first portion (F1) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; b) polymerizing portion F1 to form a solution of a first gradient polymer (PG1);

[0043] c) Add a second part (F2) to a solution containing PG1, the second part (F2) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II;

[0044] d) A portion of F2 is polymerized on PG1 to form a solution of a second-gradient polymer (PG2);

[0045] e) Add a third part (F3) to a solution containing PG2, the third part (F3) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; f) polymerize part of F3 on PG2 to form a solution containing a base polymer;

[0046] g) The solution containing the base polymer is diluted, and the base polymer is subjected to a Hofman degradation reaction to obtain a polyethyleneamine polymer, and

[0047] At least one of F1, F2, or F3 contains at least one monomer A.

[0048] At least one of F1, F2, or F3 contains at least one monomer B.

[0049] At least one of F1, F2, or F3 contains at least one compound I, and

[0050] At least one of F1, F2 or F3 contains at least one compound II.

[0051] This polymer does not contain any anionic monomers other than compound I.

[0052] The present invention also relates to a method for preparing the polyethyleneamine polymer.

[0053] The present invention also relates to a method for manufacturing paper or paperboard using the polyethyleneamine polymer.

[0054] The present invention also relates to the use of the polyethyleneamine polymer in: hydrocarbon (oil and / or natural gas) recovery; drilling or cementing (especially hydrocarbon wells); stimulation of hydrocarbon wells (oil and / or natural gas), for example, in hydraulic fracturing, conformance, and diversion; water treatment in open, closed, or semi-closed circulation systems; treatment of fermentation mash; treatment of sludge; in construction; in timber processing; in the treatment of hydraulic compositions (concrete, cement, mortar, and aggregates); in the mining industry; in cosmetic formulations; in detergent formulations; in textile manufacturing; in the geothermal field; in the manufacture of sanitary napkins; or in agriculture.

[0055] The present invention also relates to the use of polymers according to the invention as flocculants, coagulants, adhesives, fixatives, viscosity reducers, thickeners, absorbents, friction reducers, drainage agents, charge retention agents, dehydrating agents, regulators, stabilizers, fixatives, film-forming agents, sizing agents, superplasticizers, clay inhibitors, or dispersants. Detailed Implementation

[0056] "Polymer" is used to refer to a copolymer prepared using at least two different monomers, having at least one cationic monomer A and at least one nonionic monomer B, and a structured system comprising at least one compound I and at least one compound II; the "polymer" may optionally contain at least one zwitterionic hydrophilic monomer and / or one hydrophobic monomer and / or a crosslinking agent and / or a transfer agent.

[0057] Throughout this invention, the base polymer and the polyethyleneamine polymer obtained after Hofman degradation of the base polymer are water-soluble polymers.

[0058] Water-soluble polymers refer to polymers that dissolve in deionized water (concentration of 10 g·L⁻¹) when stirred at 25°C. -1 When ), a polymer containing an aqueous solution free of insoluble particles can be obtained.

[0059] In this invention, the first gradient polymer in step b) and the second gradient polymer in step d) are prepolymers.

[0060] Throughout the instructions, viscosity is measured in an aqueous solution at 25°C using a Brookfield viscometer.

[0061] This specification assumes that those skilled in the art can determine the appropriate Brookfield viscometer module and speed for the range of viscosity to be measured. In fact, this type of measurement is part of common knowledge to those skilled in the art.

[0062] "X and / or Y" means "X", or "Y", or "X and Y".

[0063] All possible combinations between the different disclosed embodiments, whether these are preferred embodiments or given as examples, are part of this invention. Furthermore, when numerical ranges are given, endpoint values ​​are included within those ranges. This disclosure also includes endpoint values ​​and all combinations between these numerical ranges. For example, the numerical range “1-20, preferably 5-15” includes the contents of “1-5”, “1-15”, “5-20”, and “15-20”, as well as the numerical values ​​1, 5, 15, and 20.

[0064] In this specification, the base polymer refers to the water-soluble polymer obtained according to the method of the present invention prior to its Hofman degradation reaction according to step g).

[0065] Basic polymers

[0066] This invention relates to a polyethyleneamine polymer produced by a Hofman degradation reaction of a base polymer, characterized by a method for obtaining it.

[0067] The basic polymer according to the present invention comprises:

[0068] -At least one cationic monomer A;

[0069] - At least one nonionic monomer B, selected from acrylamide, acrylonitrile, methacrylamide and mixtures thereof;

[0070] - At least one structured system comprising:

[0071] (i) at least one compound I, which is different from at least one monomer A, wherein compound I is selected from: allyl sulfonic acid, methyl allyl sulfonic acid, allyl disulfonic acid, methyl allyl disulfonic acid, salts thereof, and mixtures thereof;

[0072] (ii) at least one compound II of formula (1):

[0073]

[0074] R1 and R2 are independently hydrogen atoms, methyl, ethyl, isopropyl or CH2-OH groups;

[0075] R1 and R2 are not both hydrogen atoms (when R2 = H, R1 ≠ H; when R1 = H, R2 ≠ H).

[0076] The base polymer does not contain any anionic monomers other than compound I.

[0077] Monomer composition

[0078] Monomer A

[0079] The basic polymer according to the present invention is a synthetic polymer.

[0080] It may contain one or more cationic monomers (referred to as "one or more monomers A").

[0081] Advantageously, one or more cationic monomers A may be specifically selected from vinyl monomers, particularly acrylamide, acrylic acid, allyl, or maleic acid monomers having an ammonium functional group (advantageously quaternary ammonium). Specifically, but not limited to, we may mention diallyl dimethyl ammonium chloride (DADMAC), acrylamide propyltrimethyl ammonium chloride (APTAC), and methacrylamide propyltrimethyl ammonium chloride (MAPTAC), and mixtures thereof. The preferred monomer is diallyl dimethyl ammonium chloride (DADMAC).

[0082] The base polymer advantageously contains 1 to 60 mol%, preferably 2 to 50 mol%, more preferably 3 to 40 mol%, and even more preferably 4 to 30 mol% of one or more cationic monomers A.

[0083] In a preferred embodiment, the base polymer contains at least 30 mol% of one or more cationic monomers A.

[0084] Those skilled in the art know how to prepare quaternized monomers, for example, via RX-type haloalkanes, where R is an alkyl group and X is a halogen (specifically, chloromethane). Furthermore, the present invention also includes DADMAC, APTAC, and MAPTAC-type monomers, whose counter-ion halides are fluorides, bromides, or iodides, rather than chlorides.

[0085] Monomer B

[0086] The base polymer contains one or more nonionic monomers (referred to as "one or more monomers B").

[0087] As already indicated, nonionic monomer B is selected from acrylamide, acrylonitrile, methacrylamide and mixtures thereof.

[0088] The base polymer advantageously contains 40 to 99 mol%, preferably 50 to 98 mol%, more preferably 60 to 97 mol%, and even more preferably 70 to 96 mol% of nonionic monomer B.

[0089] Monomer C

[0090] The base polymer may optionally contain one or more monomers selected from the following: nonionic monomers, zwitterionic monomers, hydrophobic monomers and mixtures thereof, which are different from monomer B and compound II (referred to as "monomer C").

[0091] Advantageously, when monomer C is a nonionic monomer, it can be specifically selected from the group comprising water-soluble vinyl monomers. Preferred monomers belonging to this class are, for example, N-vinylpyrrolidone (NVP), N-vinylimidazolium, N-vinylsuccinimide, acrylamide (ACMO), glycidyl methacrylate, glyceryl methacrylate, diacetone acrylamide, N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinylpropionamide, N-vinyl-N-methylpropionamide, N-vinylbutyramide, hydroxyalkyl (C1-C3) methacrylates, thioalkyl (C1-C3) methacrylates, and mixtures thereof. N-vinylformamide is a preferred monomer.

[0092] The basic polymer of the present invention advantageously contains 0 to 40 mol%, preferably 0 to 30 mol%, of nonionic monomer C (which is different from monomer B and compound II).

[0093] Advantageously, the zwitterionic monomers used in the context of this invention are specifically selected from vinyl derivatives, specifically derivatives of acrylamide, acrylic acid, allyl, or maleic acid. Preferably, the monomer contains an amine or quaternary ammonium functional group and a carboxylic acid (or carboxyl group) functional group, a sulfonic acid (or sulfonate group) functional group, or a phosphoric acid (or phosphate group) functional group. One or more zwitterionic monomers may be selected from: dimethylaminoethyl acrylate derivatives, such as 2-((2-9-(acryloyloxy)ethyl)dimethylammonium)ethane-1-sulfonate, specifically mentioned but not limited to 3-((2-(acryloyloxy)ethyl)dimethylammonium)propane-1-sulfonate, 4-((2-(acryloyloxy)ethyl)dimethylammonium)butane-1-sulfonate, [2-(acryloyloxy)ethyl](dimethylammonium)acetate, and dimethylaminoethyl methacrylate derivatives, such as 2-((2-(methacryloyloxy)ethyl)dimethylammonium)ethane-1-sulfonate, 3-((2-(methacryloyloxy)ethyl)dimethylammonium)propane-1-sulfonate, 4-((2-(methacryloyloxy)ethyl)dimethylammonium)butane-1-sulfonate, and [2-(methacryloyloxy)ethyl](dimethylammonium)acetate. Esters, derivatives of dimethylaminoethylpropylacrylamide, such as 2-((3-acryloylpropyl)dimethylammonium)ethane-1-sulfonate, 3-((3-acryloylpropyl)dimethylammonium)propane-1-sulfonate, 4-((3-acryloylpropyl)dimethylammonium)butane-1-sulfonate, [3-(acryloyl)oxy)propyl](dimethylammonio)acetate, dimethylaminopropylmethacrylamide or even derivatives, such as 2-((3-methacryloylpropyl)dimethylammonium)ethane-1-sulfonate, 3-((3-methyldimethylammonium)propane-1-sulfonate (3-((3-me dimethylammonio)propane-1-sulfonate, 4-((3-methylacrylamidepropyl)dimethylammonium)butane-1-sulfonate and [3-(methacryloyloxy)](dimethylammonium)propyl acetate and mixtures thereof.

[0094] The applicant described other zwitterionic monomers in document WO2021123599.

[0095] The base polymer according to the invention advantageously contains 0.001 to 30 mol%, preferably 0.01 to 20 mol%, more preferably 0.1 to 15 mol% of zwitterionic monomer C.

[0096] Advantageously, one or more hydrophobic monomers C can be selected from the group consisting of: having C4-C 30 Alkyl chain, arylalkyl (C4-C) 30 Alkyl, C4-C 30 Esters of (meth)acrylic acid with propoxylated, ethoxylated, or ethoxylated and propoxylated aryl chains; having C1-C3 alkyl chains, arylalkyl (C4-C5) chains, etc. 30 Alkyl, C4-C 30 aryl) or dialkyl (C4-C) 30 Alkyl) propoxylated, ethoxylated, ethoxylated, and propoxylated (meth)acrylamide derivatives; alkyl aryl sulfonates (C4-C 30 Alkyl, C4-C 30 Aryl), or having C4-C 30 Alkyl chain, arylalkyl (C4-C) 30 Alkyl, C4-C 30 A mono- or disubstituted amide of (meth)acrylamide that is propoxylated, ethoxylated, or ethoxylated and propoxylated; having a C4-C4 ratio. 30 Alkyl chain, arylalkyl (C4-C) 30 Alkyl, C4-C 30 (aryl) or C4-C 30 Dialkyl propoxylated, ethoxylated, ethoxylated, and propoxylated (meth)acrylamide derivatives; alkyl aryl sulfonates (C4-C 30 Alkyl, C4-C 30 Aryl groups and their mixtures.

[0097] The base polymer typically contains less than 1 mol% of the hydrophobic monomer C. The base polymer may also be free of the hydrophobic monomer C.

[0098] When the base polymer according to the invention contains one or more hydrophobic monomers C, they are present in an amount that makes the polymer water-soluble.

[0099] Those skilled in the art will adjust the amounts of different monomers so that they do not exceed 100 mol% during the preparation of the base polymer. Preferably, monomers A and B account for 100 mol% of the monomers in the base polymer.

[0100] Structured system

[0101] The structured systems of basic polymers include:

[0102] (i) at least one compound I;

[0103] (ii) at least one compound II.

[0104] Compound I is advantageously selected from the following: allyl sulfonic acid, methyl allyl sulfonic acid, disulfonic acid, disulfonic methyl allyl acid, their salts and mixtures thereof, with preferred compound I being methyl allyl sulfonic acid, such as sodium methyl allyl sulfonate.

[0105] The salt formation forms advantageously correspond to alkali metal salts (Li, Na, K…), alkaline earth metal salts (Ca, Mg…), or ammonium salts (e.g., ammonium ions or tertiary ammonium). Sodium salts are preferred.

[0106] Based on the total weight of monomers A and B (+optionally, monomer C) of the base polymer, the base polymer advantageously contains 500 to 50,000 ppm, preferably 1,000 to 20,000 ppm, more preferably 2,000 to 10,000 ppm of compound I.

[0107] Compound II, used in the context of this invention, has formula (1):

[0108]

[0109] R1 and R2 are independently hydrogen atoms, methyl, ethyl, isopropyl or CH2-OH groups;

[0110] R1 and R2 are not both hydrogen atoms (when R2 = H, R1 ≠ H; when R1 = H, R2 ≠ H).

[0111] Compound II is advantageously selected from the following: N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-isopropylacrylamide, N-hydroxymethylacrylamide, and mixtures thereof. Preferably, compound II is N,N-dimethylacrylamide.

[0112] Based on the total weight of monomers A and B (+optionally, monomer C) of the base polymer, the base polymer according to the invention advantageously contains 500 to 50,000 ppm, preferably 1,000 to 20,000 ppm, more preferably 2,000 to 10,000 ppm of compound II.

[0113] In the base polymer, the mass ratio of compound I to compound II is advantageously from 0.01 to 100, preferably from 0.1 to 10.

[0114] In a preferred embodiment according to the invention, the amount of compound I is greater than the amount of compound II. Therefore, the mass ratio of compound I to compound II is advantageously greater than 1 and less than or equal to 100, preferably greater than 1 and less than or equal to 10.

[0115] Optional

[0116] The base polymer may further comprise at least one crosslinking agent. This crosslinking agent may be selected from unsaturated polyethylene monomers (having at least two unsaturated functional groups) or monomers having at least two epoxy functional groups. Examples of unsaturated polyethylene monomers include vinyl functional groups, specifically allyl functional groups and acrylic functional groups. Examples include methylenebisacrylamide (MBA), triallylamine, tetraallyl ammonium chloride, 1,2-dihydroxyethylenebis(N-acrylamide), and mixtures thereof. Preferably, the crosslinking agent is methylenebisacrylamide (MBA).

[0117] Based on the total weight of monomers A and B (+optionally, monomer C) of the base polymer, the amount of crosslinking agent in the base polymer is advantageously 5 to 5,000 ppm, more preferably 50 to 3,000 ppm.

[0118] In a specific embodiment of the invention, the base polymer does not contain a crosslinking agent.

[0119] The base polymer according to the invention may further comprise at least one transfer agent, for example selected from methanol, isopropanol, sodium hypophosphite, 2-mercaptoethanol, and mixtures thereof. Other transfer agents may also be listed, including types and mixtures of xanthates, dithiocarbonates, dithiocarbamates, and trithiocarbonates, with sodium hypophosphite being the preferred transfer agent.

[0120] Based on the total weight of monomers A and B (+optionally, monomer C) of the feed polymer, the amount of crosslinking agent in the feed polymer is advantageously contained in 10 to 10,000 ppm, more preferably 50 to 5,000 ppm.

[0121] In a specific embodiment of the invention, the raw material polymer does not contain a transfer agent.

[0122] Physical properties of basic polymers

[0123] The weight-average molecular weight of the base polymer is advantageously from 1,000,000 to 25,000,000 Daltons, preferably from 2,000,000 to 15,000,000 Daltons, and more preferably from 3,000,000 to 10,000,000 Daltons. This is the weight-average molecular weight.

[0124] Weight-average molecular weight is preferably measured by gel permeation chromatography in conjunction with a MALS detector.

[0125] The basic polymers are advantageously obtained and used in liquid form.

[0126] The viscosity of the solution containing the base polymer is advantageously 1,000 to 50,000 cps, preferably 3,000 to 20,000 cps, for example 5,000 to 20,000 cps.

[0127] renewable sources

[0128] In a preferred embodiment of the invention, the polyethyleneamine polymer is prepared using monomers that are at least partially renewable and of non-fossil origin.

[0129] In the context of this invention, the phrase "renewable and non-fossil-derived" refers to a source of compounds derived from biomass or syngas, i.e., the result of one or more chemical transformations on one or more natural and non-fossil-derived raw materials. The terms "bio-sourced" or "bio-resourced" can also be used to characterize a compound's renewable and non-fossil-derived source. A compound's renewable and non-fossil-derived source includes renewable and non-fossil feedstocks from the circular economy that have already been pre-recycled once or multiple times in the recycling of materials from biomass (e.g., materials from polymer depolymerization or pyrolysis oil conversion).

[0130] According to the present invention, "at least partially renewable and non-fossil-derived" means that, based on the total carbon weight of the compound, the content of bio-derived carbon is from 5% to 100% by weight, preferably at least 30%, more preferably at least 50%, even more preferably at least 70%, more preferably at least 90%, even more preferably at least 100% bio-derived carbon.

[0131] In the context of this invention, standard ASTM D6866-21, Method B, is used to characterize the bio-source properties of a compound and to determine the bio-source content of said compound. This value is expressed as a weight percentage of bio-source carbon based on the total weight of carbon in said compound.

[0132] gradient

[0133] The base polymer and the polyethyleneamine polymer according to the present invention are gradient polymers.

[0134] Polymers with gradient structures are polymers composed of at least two monomers, where the composition of the monomers changes gradually, unlike block polymers, whose composition changes abruptly, and random polymers, whose composition does not change continuously. In gradient polymers, inter-chain and intra-chain repulsion is rarely observed because the composition changes gradually along the polymer chain length.

[0135] Gradients can be formed spontaneously or by force. Spontaneous gradient polymerization is due to the different reactivity of monomers. Forced gradient polymerization involves changing the monomer composition introduced throughout the polymerization process.

[0136] The gradient-forced method includes (1) introducing a first monomer fraction into the reactor, (2) adding at least one additional monomer fraction (advantageously different from the first fraction), and (3) polymerizing the monomer introduced into the reactor. The monomer begins polymerization upon introduction of the first fraction.

[0137] The addition of additional monomer fractions can be carried out in parallel with the introduction of the first monomer fraction into the reactor (therefore, the introduction of fractions can begin and end simultaneously). Alternatively, the first monomer (first fraction) can begin feeding into the reactor before the addition of the second monomer fraction begins. Alternatively, the first and second fractions can be introduced simultaneously, but the time required to add the second fraction may be longer than the time required to add the first fraction into the reactor. This embodiment also applies to methods with at least three monomer fractions.

[0138] According to the method of the present invention, the obtained polyethyleneamine polymer is formed by the stepwise addition of monomers, i.e., preferably by a forced gradient method.

[0139] The method according to the invention comprises a first part (F1) and at least two additional parts (F2 and F3). At least one of parts F1, F2, and F3 differs from the other parts. Preferably, parts F1, F2, and F3 are different. Different parts refer to parts that have different monomer compositions (monomer ratios and / or properties) and / or compounds I and II (compound I and II ratios and / or properties).

[0140] Aggregation methods

[0141] The polyethyleneamine polymer is obtained according to the following steps:

[0142] a) forming a solution (S1) comprising at least a first portion (F1), the first portion comprising (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II;

[0143] b) A portion of F1 is polymerized to form a solution of the first gradient polymer (PG1);

[0144] c) Add a second part (F2) to a solution containing PG1, the second part (F2) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II;

[0145] d) A portion of F2 is polymerized on PG1 to form a solution of a second-gradient polymer (PG2);

[0146] e) Add a third part (F3) to a solution containing PG2, the third part (F3) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; f) polymerize part of F3 on PG2 to form a solution containing a base polymer;

[0147] g) Dilute the solution containing the base polymer and subject the base polymer to a Hofmann degradation reaction to obtain a polyethyleneamine polymer.

[0148] This method may include adding an additional component, but no additional component is added after step g) of the Hofmann degradation.

[0149] It is possible that the improved properties of the polymer obtained by the method according to the invention may be due to the fact that the polymerization is carried out stepwise and continuously, i.e. without interruption.

[0150] "Stepwise" means that the polymerization of the base polymer monomers is carried out in multiple parts (without interruption), i.e., parts are added continuously and polymerization does not stop. Different steps a) through f) are performed stepwise. That is, a first portion of monomers can be poured (in flowing form) and polymerized to form a first gradient polymer (PG1), which continues to polymerize with portion F2 to form gradient polymer PG2, which itself continues to polymerize with portion F3 to obtain the base polymer at the end of polymerization. At least one of portions F1, F2, and F3 is different from the others. Preferably, portions F1, F2, and F3 are different. Adding different portions in the polymerization method allows for the obtaining of a gradient in the composition of the base polymer.

[0151] In a particular embodiment, polymerization may be stopped after PO1 and / or PO2 and continued at different locations. In this embodiment, the gradient polymer PG formed during the preceding one or more steps is added. X Part F in X+1 (X = 1 or 2) aggregate and merge with PG X Interactions to form PG X+1 The process continues in the following steps to finally obtain the base polymer.

[0152] After polymerization is complete, the base polymer is subjected to step g). Step g) can be carried out continuously until the polymerization is finished, or at another time (later). Preferably, step g) is carried out continuously until PO3. That is, the base polymer used in step g) is no longer polymerized. However, the base polymer used in step g) undergoes post-treatment to change its chemical structure. Step g) is advantageously carried out in a reactor different from the polymer base synthesis reactor because it requires dilution of the solution containing the base polymer. It is advantageous to dilute the base polymer in water.

[0153] Hofmann degradation of polymers with amide groups is advantageously performed in step g).

[0154] In the polymerization method according to the invention, the sum of the molar percentages of the monomers in different parts is equal to the sum of the molar percentages of the monomers in the polyethyleneamine polymer.

[0155] Step a) forms a solution (S1) containing the first portion (F1).

[0156] Solution (S1)

[0157] Solution S1 typically contains:

[0158] - Solvent;

[0159] -Initiator;

[0160] - Part 1 F1.

[0161] The solvent is advantageously water, or a solvent in which the monomer and the starting polymer are soluble. Preferably, the solvent is water.

[0162] The polymerization initiator used can be any compound that dissociates into free radicals under polymerization conditions, such as organic peroxides, hydroperoxides, hydrogen peroxide, persulfates, azo compounds, and redox pairs. Water-soluble initiators are preferred. In some cases, it is advantageous to use a mixture of multiple polymerization initiators, for example, a mixture of a redox catalyst and an azo compound. Persulfates are a preferred initiator.

[0163] In one particular embodiment, solution S1 is formed by mixing solvent, initiator and a portion of F1 in a polymerization reactor.

[0164] In this particular embodiment, a portion of F1 may be added all at once, in multiple portions, or poured (in flowing form), i.e., gradually and continuously (e.g., dropwise) into the solvent / initiator mixture. Preferably, a portion of F1 is added to the polymerization reactor all at once.

[0165] In a particular embodiment of the invention, the initiator and a portion of F1 are poured (in flowing form) into the polymerization reaction containing the solvent. They can be added separately or premixed. Preferably, they are added separately.

[0166] In a preferred embodiment of the invention, the initiator is added continuously throughout the polymerization process. In this case, the initiator is advantageously added in parallel with different portions during different polymerization steps and during possible aging steps with different gradient polymers (PG1 and PG2) and the base polymer.

[0167] In this preferred embodiment of the invention, the initiator pouring time is 50 to 560 minutes, preferably 130 to 430 minutes.

[0168] Part 1 (F1)

[0169] Advantageously, based on the total weight of the monomers (A and / or B, + optional C) of the base polymer, part F1 contains 10 to 45% by weight, preferably 15 to 40% by weight, of the monomers (A and / or B, + optional C).

[0170] Based on the total number of moles of monomers in the fraction of F1, the fraction of F1 advantageously contains 0 to 65 mol%, preferably 5 to 55 mol%, of one or more cationic monomers A.

[0171] Based on the total number of moles of monomers in the fraction of F1, the fraction of F1 advantageously contains 35 to 100 mol%, preferably 45 to 95 mol%, of one or more nonionic monomers B.

[0172] Based on the total weight of monomers A and B (+optionally, monomer C) of the base polymer, part F1 advantageously contains 250 to 30,000 ppm, preferably 500 to 10,000 ppm, more preferably 1,000 to 7,000 ppm of compound I.

[0173] Based on the total weight of monomers A and B (+optionally, monomer C) of the polyethyleneamine polymer, part F1 advantageously contains 250 to 30,000 ppm, preferably 500 to 10,000 ppm, more preferably 1,000 to 5,000 ppm of compound II.

[0174] The different monomers and compounds constituting part F1 are advantageously added in solution form. These solutions can be added individually or in mixtures, either once, in multiple additions, or poured (in flow form) into the polymer reactor to form solution S1. Preferably, they are added in mixture form and in a single addition.

[0175] When pouring (in flowing form) portion F1, the pouring advantageously lasts for 10 to 80 minutes, preferably 40 to 70 minutes.

[0176] In a preferred embodiment, a portion of F1 is prepared in a reactor (polymerization reactor) before the initiator is added.

[0177] In a preferred embodiment, part F1 contains at least one monomer B, at least one compound I, and at least one compound II.

[0178] In a preferred embodiment, portion F1 contains at least one monomer A, at least one monomer B, at least one compound I, and at least one compound II.

[0179] Step b) polymerizes portion F1 to form the first gradient polymer (PG1).

[0180] Aggregate 1 (PO1)

[0181] Before polymerizing PO1, the air in the polymerization reactor can be replaced with an inert gas (such as nitrogen or argon).

[0182] Polymerization of PO1 is typically a free radical polymerization. Polymerization initiators can be used, specifically initiators that dissociate into free radicals under polymerization conditions.

[0183] The polymerization of PO1 is typically initiated at a temperature of 70 to 90°C, preferably 75 to 85°C, and then a cooling device is used to control the polymerization temperature so that it does not exceed 95°C.

[0184] The polymerization of PO1 is preferably carried out for 10 to 70 minutes.

[0185] Advantageously, polymerization begins when the first monomer, solvent, and initiator come into contact; that is, the duration of polymerization of PO1 advantageously corresponds to the duration of partial pouring of F1.

[0186] Gradient polymer (PG1)

[0187] At the end of the polymerization of PO1, a gradient polymer (PG1) is obtained.

[0188] In a specific embodiment of the invention, the gradient polymer PG1 is aged for 5 to 60 minutes, preferably 10 to 30 minutes.

[0189] "Aging" refers to maintaining the temperature of the medium at 80 to 90°C after polymerization to increase viscosity through internal branching of the polymer. The definition of aging applies to all steps of the polymerization process. Step c) Adding the second component (F2) to the solution containing PG1.

[0190] Part 2 F2

[0191] Advantageously, based on the total weight of the monomers (A and / or B, + optional C) of the base polymer, part F2 contains 30 to 80% by weight, preferably 40 to 70% by weight, of monomers (A and / or B, + optional C).

[0192] Based on the total number of moles of monomers in the fraction of F2, the fraction of F2 advantageously contains 0 to 50 mol%, preferably 0 to 40 mol%, of one or more cationic monomers A.

[0193] Based on the total number of moles of monomers in the fraction of F2, the fraction of F2 advantageously contains 0 to 100 mol%, preferably 60 to 100 mol%, of one or more nonionic monomers B.

[0194] Based on the total weight of monomers A and B (+optionally, monomer C) of the base polymer, a portion of F2 advantageously contains 250 to 30,000 ppm, preferably 500 to 10,000 ppm, more preferably 850 to 5,000 ppm, for example 1,000 to 5,000 ppm of compound I.

[0195] Based on the total weight of monomers A and B (+optionally, monomer C) of the base polymer, a portion of F2 advantageously contains 250 to 30,000 ppm, preferably 500 to 10,000 ppm, more preferably 1,000 to 5,000 ppm of compound II.

[0196] The different monomers and compounds constituting F2 are advantageously added in solution form. The solution can be added to the polymer reactor individually or as a mixture, either in one go, in multiple portions, or by pouring (in a flowing manner). Preferably, the feed is carried out in the form of a mixture and by pouring (in a flowing manner).

[0197] Adding a portion of F2 in a flowing form (e.g., dropwise) allows control over the exothermic nature of the reaction, which could otherwise be excessive even when using a cooler.

[0198] The partial F2 pouring can be advantageously sustained for 10 to 100 minutes, preferably 30 to 90 minutes.

[0199] In a preferred embodiment, part F2 contains at least one monomer A and B, at least one compound I, and at least one compound II.

[0200] Step d) involves polymerizing a portion of F2 on PG1 to form a second-gradient polymer (PG2).

[0201] Polymerization (PO2)

[0202] The polymerization of PO2 proceeds as a continuation of the polymerization of PO1; the polymerization of PO2 proceeds under the same temperature conditions (advantageously 70 to 90°C).

[0203] The polymerization of PO2 is advantageously sustained for 10 to 100 minutes, preferably 30 to 90 minutes.

[0204] The polymerization of PO2 begins with the addition of the first monomer of F2.

[0205] Advantageously, the duration of PO2 polymerization corresponds to the duration of partial F2 dumping.

[0206] Gradient polymer (PG2)

[0207] At the end of the polymerization of PO2, a gradient polymer (PG2) is obtained.

[0208] In a particular embodiment of the invention, the PG2 link is aged for 5 to 60 minutes, preferably 10 to 30 minutes.

[0209] Step e) Add the third part (F3) to the solution containing PG2.

[0210] Partial F3

[0211] Advantageously, based on the total weight of the monomers (A and / or B, + optional C) of the base polymer, part F3 contains 5 to 40% by weight, preferably 10 to 30% by weight of monomers (A and / or B, + optional C).

[0212] Based on the total number of moles of monomers in the fraction of F3, the fraction of F3 advantageously contains 0 to 50 mol%, preferably 0 to 35 mol%, of one or more cationic monomers A.

[0213] Based on the total number of moles of monomers in the fraction of F3, the fraction of F3 advantageously contains 50 to 100 mol%, preferably 65 to 100 mol%, of one or more nonionic monomers B.

[0214] Based on the total weight of monomers A and B (+optionally, monomer C) of the base polymer, part of F3 advantageously contains 0 to 10,000 ppm, preferably 10 to 5,000 ppm, more preferably 20 to 1,000 ppm of compound I.

[0215] Based on the total weight of monomers A and B (+optionally, monomer C) of the base polymer, part of F3 advantageously contains 0 to 10,000 ppm, preferably 0 to 1,000 ppm, of compound II.

[0216] The different monomers and compounds constituting F3 are advantageously added in solution form. These solutions can be added individually or as a mixture all at once, in multiple additions, or by pouring (in a flowing manner) (i.e., dripping) into the polymer reactor. Preferably, the addition is carried out as a mixture and by pouring (in a flowing manner).

[0217] Adding a portion of F3 in a flowing form (e.g., dropwise) allows control over the exothermic nature of the reaction, which could otherwise be excessive even when using a cooler.

[0218] The partial F3 pouring can be advantageously sustained for 10 to 100 minutes, preferably 30 to 90 minutes.

[0219] In a preferred embodiment, part of F3 contains at least one monomer B and at least one compound I.

[0220] In the embodiments, the amount of compound I in a portion of F3 is less than 500 ppm, preferably less than 300 ppm, more preferably less than 200 ppm, and even more preferably less than 100 ppm.

[0221] This small quantity allows for the achievement of the desired physical and unique properties of both the base polymer and the subsequent final polyethyleneimine polymer.

[0222] Step f), partially polymerizing F3 on PG2 to form the base polymer.

[0223] Polymer (PO3)

[0224] The polymerization of PO3 is carried out in the continuation of the polymerization of PO2; the polymerization of PO3 is carried out under the same time and temperature conditions as PO2 (advantageously, at 70 to 90°C for 10 to 100 minutes, preferably 30 to 90 minutes).

[0225] The polymerization of PO3 begins with the addition of a portion of the first monomer, F3.

[0226] Advantageously, the duration of PO3 polymerization corresponds to the duration of partial F3 dumping.

[0227] At the end of the polymerization of PO3, the basic polymer is obtained.

[0228] In a particular embodiment of the invention, the base polymer is allowed to age for 5 to 60 minutes, preferably 10 to 30 minutes, before removing residual monomers.

[0229] The reaction is stopped by adding an excess of initiator and / or water; this step is used to eliminate any residual monomers that may be present in the solution containing the base polymer.

[0230] Optional steps

[0231] The method according to the invention may also include additional steps, and is not limited to the steps described above.

[0232] In a particular embodiment of the invention, the polymerization method according to the invention may include the addition of additional components constituting the base polymer.

[0233] In a preferred embodiment of the invention, after step f) of polymerizing PO3 and before step g), the base polymer is allowed to age for 10 to 100 minutes, preferably 30 to 90 minutes. In the case of adding an additional component, aging is performed after the final polymerization step and before step g).

[0234] In a particular embodiment of the invention, a crosslinking agent and / or a transfer agent are added during at least one of the above steps.

[0235] In a particular embodiment of the invention, a crosslinking agent is added to portions of F1 and / or F2.

[0236] When a crosslinking agent is added, it is advantageously selected from the crosslinking agents described above.

[0237] When a crosslinking agent is added, the amount of crosslinking agent is advantageously 5 to 5,000 ppm, preferably 50 to 3,000 ppm, based on the total weight of the base polymer (monomers A, B and optional C).

[0238] In a particular embodiment of the invention, a transfer agent is added to portions F1 and / or F2.

[0239] When a transfer agent is added, it is advantageously selected from the transfer agents described above.

[0240] When the transfer agent is added, the amount of the transfer agent is advantageously 10 to 10,000 ppm, preferably 50 to 5,000 ppm, based on the total weight of the base polymer (monomers A, B and optional C).

[0241] Step g) The base polymer is subjected to a Hofmann degradation reaction to obtain a polyethyleneamine polymer.

[0242] The Hofmann degradation reaction involves converting amide or nitrile functional groups into amine functional groups using two major coefficients (expressed in molecular ratios) (e.g., by forming vinylamine monomer units);

[0243] - Coefficient α = hypohalate (alkali metal hypohalate and / or alkaline earth metal hypohalate) / amide and / or nitrile functional groups;

[0244] - Coefficient β = hydroxide (alkali metal hydroxide and / or alkaline earth metal hydroxide) / hypohalate (alkali metal hypohalate and / or alkaline earth metal hypohalate).

[0245] Hypohalates are oxygen-containing anions, such as hypochlorite (ClO). - Preferably, the hypohalite will be sodium hypochlorite.

[0246] "Basic hypohalates" are hypohalates of at least one alkali metal, such as NaOCl, KOBr, or NaOCl+KOBr. The same applies to alkaline earth metal hypohalates.

[0247] "Alkaline" is used to refer to alkali metals, with lithium, sodium, or potassium being the most favorable.

[0248] "Earth-alkaline" is used to refer to alkaline earth metals, preferably calcium or magnesium.

[0249] "Alkaline hydroxide" is used to represent the hydroxide (OH) of at least one alkali metal. - Examples of suitable alkali metal hydroxides include NaOH, KOH, or NaOH + KOH. The same applies to alkaline earth metal hydroxides. Preferably, the alkali metal hydroxide will be sodium hydroxide.

[0250] Advantageously, the Hofmann degradation reaction includes at least the following steps:

[0251] g1) Dilute (advantageously in water) the solution containing the base polymer to form a diluted base polymer solution (SD1);

[0252] g2) Add hypohalite and hydroxide to SD1 to form a diluted solution (SD2);

[0253] g3) Reactions between the basic polymer, hypohalate, and hydroxide;

[0254] g4) to obtain a solution containing a polyethyleneamine polymer (SD3).

[0255] Advantageously, in step g1), based on the weight of SD1, the concentration of the base polymer in the diluted solution SD1 of the base polymer is 1 to 40% by weight, more preferably 2 to 30% by weight, and even more preferably 5 to 25% by weight.

[0256] Advantageously, in step g2), the α coefficient is equal to the hypohalate / amide and / or nitrile functional group, and the α coefficient is 0.1 to 1.0, preferably 0.3 to 1.0, more preferably 0.5 to 1.0.

[0257] Advantageously, in step g2), the β coefficient = hydroxide / hypohalate, and the β coefficient is 0.5 to 4.0.

[0258] Advantageously, in step g3), the reaction between the base polymer, the hypohalate and the hydroxide lasts from 10 seconds to 180 minutes, preferably from 1 minute to 120 minutes, more preferably from 10 minutes to 90 minutes, and even more preferably from 30 minutes to 75 minutes.

[0259] Advantageously, in step g3), the reaction between the base polymer, the hypohalate and the hydroxide is carried out at a temperature of 10 to 30°C, preferably 15 to 25°C.

[0260] At the end of step g3), the polyethyleneamine polymer according to the present invention is obtained.

[0261] In a particular embodiment of the invention, at the end of step g3), the polyethyleneamine polymer can be functionalized with dialdehyde to generate an aldehyde-functionalized polymer (advantageously glyoxalization).

[0262] The dialdehyde is advantageously selected from glyoxal, glutaraldehyde, furanyl dialdehyde, adipaldehyde, succinaldehyde, dialdehyde starch, 2,2-dimethoxyacetaldehyde, diepoxides, and mixtures thereof. Preferably, the dialdehyde is glyoxal.

[0263] To stabilize the generated amine functional groups, those skilled in the art can add at least one quaternary ammonium derivative, as described in document JP 57077398, to the diluted solution SD1. This quaternary ammonium derivative is intended to prevent reaction between the amine functional groups and the residual amide functional groups. Furthermore, these reagents can be added individually, simultaneously, mixed, or undiluted, in any order of introduction, at one or more injection sites. The addition of these reagents is advantageously carried out during step g1).

[0264] In a preferred embodiment of the invention, the pH of solution SD3 is adjusted to 0.5 to 7.5, more preferably 1.0 to 3.0, by adding an acid. This pH adjustment is advantageously carried out when the polyethyleneamine polymer is not functionalized by a compound containing at least two aldehyde functional groups.

[0265] During Hofmann degradation, the cationicity of the base polymer increases due to the complete or partial use / consumption of alkali metal hypohalates or alkaline earth metal hypohalates.

[0266] The cationic charge density of the polyethyleneamine polymer is advantageously greater than 2 meq / g, preferably greater than 5 meq / g, advantageously less than 12 meq / g, and preferably less than 11.5 meq / g.

[0267] In a particular embodiment of the invention, the microcellulose compound is reacted with a polyethyleneamine polymer.

[0268] Advantageously, the microcellulose compound is in the form of a suspension in water.

[0269] Advantageously, during the reaction with the microcellulose compound, the mass concentration of the polyethyleneamine polymer in the aqueous solution is 0.5% to 20%, preferably 1% to 5%.

[0270] The reaction between the microcellulose compound and the polyethyleneamine polymer is advantageously carried out when the polyethyleneamine polymer is not functionalized with dialdehyde.

[0271] The reaction between the microcellulose compound and the polyethyleneamine polymer is advantageously carried out at a temperature of 10°C to 60°C, preferably 20°C to 40°C.

[0272] Advantageously, the microcellulose compound is selected from the following: nanofibrillated cellulose, microfibrillated cellulose, nanocrystalline cellulose, and nanocellulose.

[0273] Advantageously, based on the weight of the polyethyleneamine polymer, 10% to 100% by weight, preferably 10% to 50% by weight, of a microcellulose compound is added to the polyethyleneamine polymer.

[0274] Even if the polyethyleneamine polymer is prepared in solution, the polyethyleneamine polymer of the present invention can also be used in solid form. Under these conditions, the solid form contains not only the polymer but also a portion of the salts obtained at the end of the Hofmann degradation. In practice, the solid form of the polyethyleneamine polymer is obtained by other means (by a solution method including a drying step g). The technical principle of solid / liquid separation is through atomization or spray drying (which involves generating a fine droplet in a hot gas stream for a controlled period of time), drum drying, fluidized bed dryers...

[0275] Papermaking methods

[0276] The present invention also relates to a method of manufacturing paper or paperboard, comprising (1) adding a polyethyleneamine polymer according to the invention to an aqueous solution of fibers, and (2) forming paper or paperboard. Therefore, the present invention relates to the use of polyethyleneamine polymers in papermaking methods.

[0277] The various steps in papermaking processes, paperboard production processes, or similar methods are known and fall within the scope of knowledge of those skilled in the art. It is unnecessary to describe these steps in further detail, as they are known and classic to the best of the knowledge of those skilled in the art. If necessary, those skilled in the art may refer to the following literature: Handbook for Pulp & Paper Technologists, 4th Edition, GASmook.

[0278] According to the present invention, a polyethyleneamine polymer is added during the papermaking process, either before or after the formation of paper, paperboard, or the like. Therefore, contact between cellulose materials and the polymers of the present invention can be carried out in various ways, particularly according to typical methods known to those skilled in the art.

[0279] Polyvinylamine polymers can be added to cellulosic materials in the form of diluted or undiluted aqueous solutions. Polyvinylamine polymers can be applied via impregnation techniques or added directly to the fiber suspension in papermaking processes, wherever dry strength agents are typically introduced.

[0280] Therefore, the polymer according to the invention can be introduced into thick or thin slurries. The polymer according to the invention can be added at the mixing pump, before the headbox, or before the filter. Preferably, the polymer is introduced before the headbox.

[0281] Preferably, the polymer according to the invention is industrially injected into a fiber suspension, i.e., before it is diluted with white water (thick slurry). The consistency of the slurry is about 1 to 5% by mass of cellulose fibers.

[0282] The papermaking method according to the invention can be implemented with any type of pulp (e.g., virgin fiber pulp (kraft paper, bisulfite), recycled fiber, deinking pulp, mechanical pulp and thermomechanical pulp).

[0283] Polyvinylamine polymers can be advantageously added directly to the fiber suspension before paper formation.

[0284] Polyethyleneamine polymers can be added at a single injection point or at two injection points.

[0285] As needed, the papermaking method according to the present invention may further include the addition of other additives and / or polymers; as non-limiting examples, we may mention: biocides, coagulants, retention aids, flocculants, starch.

[0286] use

[0287] The present invention also relates to the use of the polyethyleneamine polymer in: hydrocarbon (oil and / or natural gas) recovery; drilling or cementing (especially hydrocarbon wells); stimulation of hydrocarbon wells (oil and / or natural gas), for example, in hydraulic fracturing, conformance, and diversion; water treatment in open, closed, or semi-closed circulation systems; treatment of fermentation mash; treatment of sludge; in construction; in timber processing; in the treatment of hydraulic compositions (concrete, cement, mortar, and aggregates); in the mining industry; in cosmetic formulations; in detergent formulations; in textile manufacturing; in the geothermal field; in the manufacture of sanitary napkins; or in agriculture.

[0288] The present invention also relates to the use of polyethyleneamine polymers as flocculants, coagulants, adhesives, fixatives, viscosity reducers, thickeners, absorbents, friction reducers, drainage agents, charge retention agents, dehydrating agents, regulators, stabilizers, fixatives, film-forming agents, sizing agents, superplasticizers, clay inhibitors, or dispersants.

[0289] The invention and its advantages will be more clearly shown in the following examples, which are used to illustrate the invention but are not intended to limit its use.

[0290] Example

[0291] List of abbreviations:

[0292] DADMAC: Diallyl dimethylammonium (monomer A)

[0293] AMD: Acrylamide (monomer B)

[0294] DMAM: Dimethylacrylamide (Compound II)

[0295] SMS: Sodium methyl allyl sulfonate (Compound I)

[0296] SPS: Sodium persulfate (polymerization initiator)

[0297] MBA: Methylenebisacrylamide (crosslinking agent)

[0298] PEI: Polyethyleneimine

[0299] Description of GPC-MALS molecular weight characterization

[0300] Gel permeation chromatography is a method for separating macromolecules based on their hydrodynamic volume. When combined with MALS detection, gel permeation chromatography allows for the measurement of light diffusion from multiple angles.

[0301] The synthesized polymers were analyzed under the following conditions:

[0302] -Instrument: GPC-2

[0303] - Column: Shodex SB-807-HQ and SB-805 Custom

[0304] -method:

[0305] * Temperature: 30℃

[0306] * Mobile phase: 0.5M NaNO3, HEPES (pH=8), 100ppm NaN3

[0307] * Injection: 100μL

[0308] * Flow rate: 0.3 mL / min

[0309] * Detection:

[0310] (i) Photodiffusion Detector (MALS): Absolute Molar Mass

[0311] (ii) Refractometer (RI): Concentration

[0312] Viscosity was measured at 25°C using a Brookfield viscometer with a Brookfield LV1 module at 60 rpm.

[0313] Preparation of polymer 1 according to the present invention (P1(INV))

[0314] Polymer 1 (P1)

[0315] Step 1: Gradient polymer PG1

[0316] In a 1-liter reactor equipped with a mechanical stirrer, thermometer, condenser, and nitrogen-impregnated rod, a first component F1, consisting of the following: 146.9 g water, 50.6 g acrylamide (50% by weight aqueous solution), 77.1 g dimethyl diallyl ammonium chloride (64% by weight aqueous solution), 1 g citric acid, 0.5 g dimethylacrylamide, and 0.4 g sodium methylallyl sulfonate. The medium is heated using a water bath and maintained at a temperature of 79 to 81 °C. The addition of 0.05 g sodium persulfate allows the initiation of this starting material and the start of monomer polymerization (PO1) to form a solution of the first gradient polymer PG1.

[0317] Step 2: Gradient polymer PG2

[0318] When the exothermic reaction is complete, begin pouring: pour the initiator (50 g SPS, 0.33 wt% aqueous solution) over 130 minutes, and simultaneously pour the second portion F2 over 50 minutes, which consists of: 25.5 g water, 101.3 g acrylamide (50 wt% aqueous solution), 77.1 g DADMAC (64 wt% aqueous solution), 0.5 g dimethacrylamide, and 0.19 g sodium methyl allyl sulfonate. After pouring the portion of F2, allow the gradient polymer PG2 to age for 10 minutes (PO2 is polymerized during the pouring of the portion of F2 and during aging to form the gradient polymer PG2).

[0319] Step 3: Basic Polymer

[0320] Then, we began pouring the third portion, F3, over 60 minutes, which consisted of: 121.3 g water, 50.6 g acrylamide (50% by weight aqueous solution), and 0.01 g sodium methyl allyl sulfonate. At the end of the addition of portion F3, the polymer was allowed to age for 10 minutes (PO3 was polymerized during the pouring of portion F3 and during aging to form the base polymer).

[0321] After aging, 146.9 g of water and 0.15 g of sodium persulfate were added. When the desired viscosity was reached, the reaction was stopped by adding 0.6 g of sodium bisulfite (40 wt% aqueous solution) and 146.9 g of water. A new aging cycle of 60 minutes was applied before cooling. The resulting solution containing base polymer 1 had a pH of 3.5, 20 wt% active material, a viscosity of 3500 cps, and a molecular weight of 2,650,000 Da obtained by GPC-MALS.

[0322] Hofmann degradation: Polymer 1 (P1)

[0323] Hofmann degradation was performed according to the applicant's method described in document WO2010061082. At the end of the Hofmann degradation, the polyethyleneamine polymer (P1(INV)) according to the present invention was obtained.

[0324] Preparation of comparative polymers 2 to 3 (CE1 to CE2)

[0325] Polymer 2 (CE1)

[0326] According to Example E of document WO2011015783, polymer 2 (CE1) was obtained by Hofmann degradation reaction.

[0327] Polymer 3 (CE2)

[0328] Polymer 3 (CE2) was prepared using the same method as polymer 1, but with only two steps.

[0329] The composition of different parts of the polymerization methods of polymer 1 (P1) and comparative polymers (CE1 to CE2) according to the present invention is summarized in Table 1a.

[0330] In Table 1a, the monomer content described in each section represents the molar weight percentage of the AMD (or DADMAC) monomer relative to the total molar amount of the corresponding monomer in the total section. Therefore, for example, the sum of the percentages of the AMD monomer in the three sections equals 100%.

[0331] The contents of compounds I (SMS) and II (DMAM) are expressed in ppm by weight, based on the total weight of one or more monomers in the three parts.

[0332]

[0333] Table 1a: Composition of the polymerization method portion for obtaining polymer P1 and comparative examples P2 to P3 (CE1 to CE2).

[0334] The physicochemical properties of the obtained basic polymers P1 and CE1 to CE2 are described in Table 1b below:

[0335]

[0336] Table 1b: Physicochemical properties of the raw material polymer P1 and comparative examples CE1 to CE2 according to the present invention.

[0337] We have observed the differences and benefits offered by the present invention compared to existing technologies, particularly regarding the molecular weight of the base polymer (even if the viscosity is on the same order of magnitude).

[0338] Table 1c below shows the viscosity results of the final polymer obtained after the Hofmann degradation reaction.

[0339]

[0340] Table 1c: Comparison of the viscosity of polymer P1 of the present invention and comparative examples CE1 to CE3 after Hofmann degradation.

[0341] The method of the present invention provides a polymer solution having the viscosity required and typical for papermaking processes, while having a high molecular weight compared to conventional polymerization methods.

[0342] Application testing

[0343] The wet pulp used in all application examples was obtained by breaking down dry pulp to achieve a final water concentration of 1%. This is a pH-neutral pulp with 100% recycled paperboard fibers. Evaluation of Vacuum Drainage (DDA) performance.

[0344] The DDA (Dynamic Drainage Analyzer) allows for the automatic determination of the time (in seconds) required for vacuum dehydration of the fiber suspension on the fabric. The polymer is added to the wet pulp (0.6 liters of pulp, 1.0% by mass) in the DDA cylinder with stirring at 1000 rpm:

[0345] T=0s: Stirring the pulp

[0346] T = 10s: Add one or more polymers

[0347] T = 30s: Stop stirring and vacuum drain for 60 seconds at 200mbar.

[0348] The pressure under the fabric is recorded as a function of time. As water drains from the fiber pad, air passes through it, causing a sudden change in the slope of the curve representing the pressure under the fabric as a function of time. The time (in seconds) associated with this sudden change in slope on the curve corresponds to the drainage time. Therefore, the shorter this time, the better the vacuum drainage.

[0349] Performance in dry applications, based on a weight of 80 g·m-2

[0350] Take a sample of the necessary amount of pulp to ultimately obtain a pulp with a particle size of 80 g·m³. -2 The base weight of the paper.

[0351] The wet pulp is introduced into the dynamic hand-made paper forming machine tank and kept agitated. Different compounds are injected into the pulp in a predetermined sequence. Typically, there is a contact time of 30 to 45 seconds between the addition of polymers.

[0352] Papermaking using an automated dynamic paper forming machine: Before the tank begins rotating at 1000 rpm and a water wall is built, blotting paper and the formed fabric are placed into the tank of the dynamic paper forming machine. The treated pulp is distributed on the water wall to form a fibrous mat on the formed fabric.

[0353] After the water was drained, the fiber pads were recycled, pressed under a pressure of 4 bar, and then dried at 117°C. The resulting paper was packaged overnight in a room with controlled humidity and temperature (50% relative humidity and 23°C). The dryness resistance of all the paper obtained through this step was then measured.

[0354] The fracture strength was measured using a Messmer Buchel M 405 fracture tester according to the TAPPI T403 om-02 standard.

[0355] According to the TAPPI T494 om-01 standard, the fracture length under dry conditions was measured using a machine equipped with a Testometric AX traction device.

[0356] The amount of polymer added is expressed in kg of active polymer per ton of dry fiber.

[0357] Experiments were conducted at 1 kg / t and 1.5 kg / t, and the results are summarized in Table 2. The results are expressed as the percentage increase compared to the control group (no polymer).

[0358]

[0359] Table 2: Drainage and dry strength results of polymer 1 (INV) and comparative polymers 2 to 3 (CE1 to CE2) according to the present invention

[0360] Interestingly, it is noted that the polymers of the present invention exhibit improved drainage performance (DDA) and mechanical properties (cracking; DBL; cracking in a dry state) compared to the most effective products on the market.

Claims

1. A polyethyleneamine polymer obtained by the Hofmann degradation reaction of a base polymer, said base polymer comprising: - At least one cationic monomer A, selected from the following: dimethyl diallyl ammonium chloride, acrylamidopropyltrimethyl ammonium chloride, methacrylamidopropyltrimethyl ammonium chloride and mixtures thereof; - At least one nonionic monomer B, selected from the following: acrylamide, acrylonitrile, methacrylamide and mixtures thereof; - At least one compound I, selected from the following: allyl sulfonic acid, methyl allyl sulfonic acid, allyl disulfonic acid, methyl allyl disulfonic acid, salts thereof, and mixtures thereof; - At least one compound II of formula (1): R1 and R2 are independently hydrogen atoms, methyl, ethyl, isopropyl or CH2-OH groups; R1 and R2 are not both hydrogen atoms; The polymer does not contain any anionic monomers other than compound I; The base polymer comprises 1 to 60 mol% of one or more cationic monomers A and 40 to 99 mol% of one or more nonionic monomers B; Based on the total weight of monomers A and B, the base polymer contains 500 to 50,000 ppm of compound I; Based on the total weight of monomers A and B, the base polymer contains 500 to 50,000 ppm of compound II; The mass ratio between compound I and compound II is from 0.01 to 100; The polyethyleneamine polymer is obtained according to the following steps: a) forming a solution (S1) comprising at least a first portion (F1), wherein the first portion (F1) contains (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; b) A portion of F1 is polymerized to form a solution of the first gradient polymer (PG1); c) Add a second part (F2) to a solution containing PG1, the second part (F2) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; d) A portion of F2 is polymerized on PG1 to form a solution of a second-gradient polymer (PG2); e) Add a third part (F3) to a solution containing PG2, said third part (F3) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; f) A portion of F3 is polymerized on PG2 to form a solution containing the base polymer; g) Dilute the solution containing the base polymer and subject the base polymer to a Hofmann degradation reaction to obtain a polyethyleneamine polymer. At least one of F1, F2, or F3 contains at least one monomer A. At least one of F1, F2, or F3 contains at least one monomer B. At least one of F1, F2, or F3 contains at least one compound I, and At least one of F1, F2 or F3 contains at least one compound II.

2. The polyethyleneamine polymer according to claim 1, characterized in that, Compound II is selected from the following: N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-isopropylacrylamide, N-hydroxymethylacrylamide and mixtures thereof.

3. The polyethyleneamine polymer according to claim 1, characterized in that, At least one of the parts F1, F2 or F3 is different from the other parts.

4. A method for stepwise preparation of polyethyleneamine polymers, comprising the following steps: a) forming a solution (S1) comprising at least a first portion (F1), wherein the first portion (F1) contains (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; At least one monomer A is a cationic monomer selected from the following: dimethyl diallyl ammonium chloride, acrylamidopropyltrimethyl ammonium chloride, methacrylamidopropyltrimethyl ammonium chloride, and mixtures thereof; At least one monomer B is a nonionic monomer selected from the following: acrylamide, acrylonitrile, methacrylamide and mixtures thereof; At least one compound I is selected from the following: allyl sulfonic acid, methyl allyl sulfonic acid, allyl disulfonic acid, methyl allyl disulfonic acid, salts thereof, and mixtures thereof; At least one compound II having formula (1): R1 and R2 are independently hydrogen atoms, methyl, ethyl, isopropyl or CH2-OH groups; R1 and R2 are not both hydrogen atoms; The polymer does not contain any anionic monomers other than compound I; b) A portion of F1 is polymerized to form a solution of the first gradient polymer (PG1); c) Add a second part (F2) to a solution containing PG1, the second part (F2) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; d) A portion of F2 is polymerized on PG1 to form a solution of a second-gradient polymer (PG2); e) Add a third part (F3) to a solution containing PG2, said third part (F3) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; f) A portion of F3 is polymerized on PG2 to form a solution containing the base polymer; g) Dilute the solution containing the base polymer and subject the base polymer to a Hofmann degradation reaction to obtain a polyethyleneamine polymer, and The base polymer comprises 1 to 60 mol% of one or more cationic monomers A and 40 to 99 mol% of one or more nonionic monomers B; Based on the total weight of monomers A and B, the base polymer contains 500 to 50,000 ppm of compound I; Based on the total weight of monomers A and B, the base polymer contains 500 to 50,000 ppm of compound II; The mass ratio between compound I and compound II is from 0.01 to 100; and At least one of F1, F2, or F3 contains at least one monomer A. At least one of F1, F2, or F3 contains at least one monomer B. At least one of F1, F2, or F3 contains at least one compound I, and At least one of F1, F2 or F3 contains at least one compound II.

5. The method according to claim 4, characterized in that, At least one of the parts F1, F2 or F3 is different from the other parts.

6. The method according to claim 4 or 5, characterized in that... The initiator is added continuously throughout the polymerization process.

7. The method according to claim 4 or 5, characterized in that, After step f) of polymerization (PO3) and before step g), the method includes an aging step of 10 to 100 minutes.

8. The method according to claim 4 or 5, characterized in that, The Hofmann degradation reaction includes at least the following steps: g1) Dilute the solution containing the base polymer to obtain a diluted solution of the base polymer (SD1); g2) Add alkali metal hypohalate or alkaline earth metal hypohalate and alkali metal hydroxide or alkaline earth metal hydroxide to obtain a diluted solution (SD2); g3) Reactions between basic polymers, alkali metal hypohalates or alkaline earth metal hypohalates and alkali metal hydroxides or alkaline earth metal hydroxides; g4) to obtain a solution containing a polyethyleneamine polymer (SD3).

9. A method for manufacturing paper or paperboard, comprising: Add the polyethyleneamine polymer according to any one of claims 1 to 3 to an aqueous suspension of fibers, and form paper or paperboard.

10. Uses of the polyethyleneamine polymer according to any one of claims 1 to 3: in hydrocarbon recovery; in drilling or cementing; in enhancing the production of hydrocarbon wells; in water treatment in open, closed, or semi-closed circulation systems; in the treatment of fermentation mash; in the treatment of sludge; in construction; in wood processing; in the treatment of hydraulic compositions; in the mining industry; in the formulation of cosmetics; in the formulation of detergents; in the manufacture of textiles; in the geothermal field; in the manufacture of sanitary napkins; or in agriculture.

11. The polyethyleneamine polymer according to any one of claims 1 to 3 is used as a flocculant, coagulant, adhesive, fixative, viscosity reducer, thickener, absorbent, friction reducer, drainage agent, charge retention agent, dehydrating agent, regulator, stabilizer, fixative, film-forming agent, sizing agent, superplasticizer, clay inhibitor, or dispersant.

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